EP-4739217-A1 - PATIENT HANDLING SYSTEMS FOR MEDICAL IMAGING APPARATUS

Abstract

A patient handling systems (PHS) for medical imaging apparatus positions a patient on a patient bed in and out of an imaging field of view. A trolley carrying the patient bed translates linearly on a frame. The weight load of the patient bed is transferred to the frame along a load direction. The system incorporates a linear motor, having a rotor coupled to the trolley and a linear stator coupled to the frame in mutually opposed orientation, separated by a motor gap. The system also incorporates a linear motion encoder, having a sensing head coupled to the trolley and a linear encoder tape coupled to the frame in mutually opposed orientation, separated by a sensor gap. Both the motor and sensor gaps are oriented parallel to the weight load direction, to reduce likelihood of either gap variation attributable to load deflection of the frame.

Inventors

• Knodt, Konstantin
• NEUBER, WOLFGANG
• STOCK, JOHANNES
• BAUMANN, BERTHOLD

Assignees

• Siemens Medical Solutions USA, Inc.

Dates

Publication Date

20260513

Application Date

20240201

Claims (20)

1. 1. A patient handling system for a medical imaging apparatus, comprising: a frame with a longitudinal length, defining a central longitudinal axis, and an upper surface; first and second linear rails respectively coupled to the frame, oriented parallel to the central longitudinal axis; first and second runner blocks, respectively slidably coupled to the first and second linear rails; a trolley commonly coupled to the first and second runner blocks, the trolley slidably mounted over the upper surface of the frame and translatable along the central longitudinal axis; a cantilevered patient bed coupled to the trolley, so that weight load of the patient bed is transferred to the frame along a first load direction through the trolley, the first runner block and the first linear rail and along a second load direction through the trolley, the second runner block and the second linear rail; at least one linear motor, having a rotor and a linear stator in opposed orientation, separated by a motor gap, the rotor coupled to the trolley and the linear stator coupled to the frame in orientation parallel to the central longitudinal axis, with the motor gap oriented parallel to at least one of the first or second load directions; and at least one linear motion encoder, having a sensing head and a linear encoder tape in opposed orientation, separated by an encoder gap, the sensing head coupled to the trolley or one of the first or the second runner blocks, and the linear encoder tape coupled to the frame in orientation parallel to the frame central longitudinal axis, with the encoder gap oriented parallel to at least one of the first or second load directions.
2. 2. The patient handling system of claim 1, further comprising the first and second linear rails having respective first and second mounting surfaces coupled to the frame, the first and second linear rails oriented so that the respective first and second load directions are parallel to and apply a shearing load on the respective mounting surfaces.
3. 3. The patient handling system of claim 1, further comprising the first and second linear rails having first and second mounting surfaces coupled to the frame, the linear rails oriented so that the respective first and second load directions are oriented normal to and apply a tensile load to the respective mounting surfaces.
4. 4. The patient handling system of claim 1, the frame comprising: opposed, laterally spaced, outer first and second walls, commonly joined and bridged by a transverse-oriented third wall, all of the first, second and third walls parallel to the central longitudinal axis; the first and second linear rails respectively coupled to the respective first and second walls; and a u-shaped, open cavity that is in communication with the upper surface of the frame, the open cavity oriented between the first and second walls.
5. 5. The patient handling system of claim 4, the frame further comprising respective fourth and fifth walls oriented inboard of the first and second walls that are commonly coupled by the transverse third wall, all of said first through fifth walls parallel to the central longitudinal axis, the third, fourth and fifth walls collectively defining the u-shaped, open cavity that is in communication with an upper surface of the frame.
6. 6. The patient handling system of claim 5, further comprising the linear motor oriented in the cavity, with the rotor coupled to the trolley by a motor support extending into the cavity and the linear stator coupled to either the fourth wall or the fifth wall.
7. 7. The patient handling system of claim 5, further comprising the sensing head coupled to one of the runner blocks and the linear encoder coupled to one of the first or second or fourth or fifth walls.
8. 8. The patient handling system of claim 5, the frame further comprising a transverse oriented sixth wall joining the outer, first wall and the inboard, fifth wall, and a transverse oriented seventh wall joining the outer, second wall and the inboard, fifth wall.
9. 9. The patient handling system of claim 8, the frame further comprising a metal monolithic block formed by a metal extrusion process.
10. 10. The patient handling system of claim 5, further comprising the first and second linear rails having respective first and second mounting surfaces coupled to the respective first and second walls; the first and second linear rails oriented so that the respective first and second load directions are parallel to and apply a shearing load on the respective mounting surfaces.
11. 11. The patient handling system of claim 5, further comprising the first and second linear rails having first and second mounting surfaces coupled to the respective first and second walls; the linear rails oriented so that the respective first and second load directions are oriented normal to and apply a tensile load to the respective mounting surfaces.
12. 12. The patient handling system of claim 5, further comprising a continuous planar, flexible belt covering the open cavity, respective longitudinal ends of the belt coupled to respective longitudinal ends of the frame, the belt passing between opposed rollers that are coupled to the trolley.
13. 13. The patient handling system of claim 12, the frame further comprising first and second drip rails coupled to the outer surface of the frame along lateral edges of the cavity, below lateral edges of the flexible belt.
14. 14. The patient handling system of claim 5, the frame further comprising floor mounting lugs coupled to outer facing surfaces of the first and second walls.
15. 15. The patient handling system of claim 5, further comprising a drag chain oriented in the cavity for providing electrical power to the linear motor and/or the trolley, one end of the drag chain coupled to the frame and the other end of the drag chain coupled to the trolley.
16. 16. A patient handling system for a medical imaging apparatus, comprising: a frame with a longitudinal length, defining a central longitudinal axis and an upper surface, having: opposed, laterally spaced, outer first and second walls, commonly joined and bridged by a transverse-oriented third wall; fourth and fifth walls oriented inboard of the first and second walls that are commonly coupled by the transverse third wall, all of said first through fifth walls parallel to the central longitudinal axis, the third, fourth and fifth walls collectively defining a u-shaped, open cavity that is in communication with the upper surface of the frame; a transverse oriented sixth wall joining the outer, first wall and the inboard, fourth wall, and a transverse oriented seventh wall joining the outer, second wall and the inboard, fifth wall; the sixth and seventh walls forming lateral edges of the cavity that are parallel to the longitudinal axis; the frame constructed as a metal monolithic block, formed by a metal extrusion process; first and second linear rails respectively coupled to the respective first and second walls, oriented parallel to the central longitudinal axis; first and second runner blocks, respectively slidably coupled to the first and second linear rails; a trolley commonly coupled to the first and second runner blocks, the trolley slidably mounted over the upper surface of the frame and translatable along the central longitudinal axis; a cantilevered patient bed coupled to the trolley, so that weight load of the patient bed is transferred to the frame along a first load direction through the trolley, the first runner block and the first linear rail and along a second load direction through the trolley, the second runner block and the second linear rail; at least one linear motor having a rotor and a linear stator in opposed orientation, separated by a motor gap, the rotor coupled to the trolley by a motor support extending into the cavity, and the linear stator coupled to the fourth wall or the fifth wall, in orientation parallel to the central longitudinal axis, with the motor gap onented parallel to at least one of the first and second load directions; and at least one linear motion encoder, having a sensing head and a linear encoder tape in opposed orientation, separated by an encoder gap, the sensing head coupled to the trolley or one of the first or the second runner blocks and the linear encoder coupled to the frame in orientation parallel to the frame central longitudinal axis, with the encoder gap oriented parallel to at least one of the first or second load directions.
17. 17. The patient handling sy stem of claim 16, further comprising the first and second linear rails having respective first and second mounting surfaces coupled to the respective first and second walls; the first and second linear rails oriented so that the respective first and second load directions are parallel to and apply a shearing load on the respective mounting surfaces.
18. 18. The patient handling system of claim 16, further comprising the first and second linear rails having first and second mounting surfaces coupled to the respective first and second walls; the linear rails oriented so that the respective first and second load directions are oriented normal to and apply a tensile load to the respective mounting surfaces.
19. 19. The patient handling system of claim 16, further comprising: a continuous planar, flexible belt covering the open cavity, respective longitudinal ends of the belt coupled to respective longitudinal ends of the frame, the belt passing between opposed rollers that are coupled to the trolley; and a first drip rail coupled to the sixth wall, and a second drip rail coupled to the seventh wall, both drip rails coupled to the outer surface of the frame along lateral edges of the cavity, below lateral edges of the flexible belt.
20. 20. The patient handling system of claim 16, further comprising a drag chain oriented in the cavity for providing electrical power to the linear motor and/or the trolley, one end of the drag chain coupled to the frame and the other end of the drag 4 chain coupled to the trolley.

Description

PATIENT HANDLING SYSTEMS FOR MEDICAL IMAGING APPARATUS PRIORITY CLAIM [0001] This application claims the benefit of priority of United States Provisional Application Number 63/518,328, filed August 9, 2023, and entitled “Highly Integrated Floor Axis for Constant Deflection PHS” which is incorporated by reference herein. TECHNICAL FIELD [0002] The disclosure relates to patient handling systems (PHS) for diagnostic medical imaging apparatus. More particularly, the disclosure relates to motorized patient handling systems for positioning of patients in and out of an imaging field of view of the imaging apparatus, such as an imaging tunnel. BACKGROUND [0003] Diagnostic medical imaging apparatuses include, by way of non-limiting example computed tomography (CT), two-dimensional digital radiography (DR), positron emission tomography (PET), magnetic resonance imaging (MRI), PET/CT, and PET/MRI modalities. FIGs. 1-4 depict a known PET scanner 20 that includes a toroidal-shaped, rotating gantry structure 22, with a patient tube 24 through which is inserted a cantilever-supported patient bed 26. Within patient tube 24, the scanner 20 establishes an imaging field of view (FoV) with a horizontal scan axis. A motorized patient handling system (PHS) 28, selectively translates the cantilever-mounted patient bed 26 linearly on a floor-mounted frame 30, advancing and retracting the latter in and out of the patient tube 24. Frame 30 supports patient bed 26 and patient weight load. The PHS 28 is generally suitable for use with various modalities of medical imaging apparatus that require translation of a patient bed within an imaging FoV established within a patient tube 24. [0004] The horizontal scan axis of the PET scanner 20 is axially aligned with the longitudinal axis X of the PHS 28 and its patient bed 26. Given the cantilevered mounting orientation of the patient bed 26 on the frame 30 it is desirable to maintain the same constant deflection in the direction of the patient load (vertical axis Z) throughout the full translation range of the bed on the frame. Such constant deflection enhances the image quality of the scan. In PET-CT systems where the two respective field of views (FoV) are in series within a common patient tube that is generally longer than that of single modality PET or CT systems, its patient bed must have sufficient longitudinal length in the X axis direction to be able to translate the patient fully through both of the scanner FoV’s. It is desirable that both FoV’s have the same constant deflection. This property improves the image quality of each of the respective FoV’s itself as well as the superimposition of the image data of both FoV’s for diagnostic evaluation of the patient. [0005] Referring again to FIGs. 1-4. in order to optimize constant load deflection of patient bed 26 (Z axis) throughout its full translation range (X axis) of the PHS 28. frame 30 has been constructed with two planar plates. Prior art construction of the floor axis of a PET patient bed consists of one or more (here, two) flat metal plates 32 and 34, which are retained by a matrix array of anchoring studs 36 that are embedded within, glued to, and projecting from the floor 38 of the imaging room. Typically, plates 32 and 34 are constructed of aluminum. A pair of linear rails 40 having a respective mounting surface 42 are screwed onto these two plates 32 and 34 and are aligned with the longitudinal axis X of the PHS 28. A corresponding pair of runner blocks 44 are slidably coupled to the respective linear rails 40. The runner blocks 44 are coupled to a trolley 46 that retains the patient bed 26. The runner blocks 44 are pre-tensioned to compensate for a specified patient load to be applied to patient bed 26 and trolley 46, calculated to offset the patient load that would otherwise deflect the linear rails 40 downwardly in the Z direction. Notwithstanding runner block 44 pretensioning. deflection loads attributable to patient load and/or floor deflection, and/or torsional offset loads of the patient on the cantilevered patient bed 26 may twist the trolley 46 and its attached runner blocks orientation relative to its linear rail. This twisting load effectively applies a translation-resisting clamping force between the runner blocks and the rail that is in turn transferred as a buckling force on the flat plates 32 and 34. Buckling forces applied to the flat plates 32 and 34 is resisted by a relatively large number of anchoring studs 36. Typically, 64 or more anchoring studs 36 are required for installation of known frames 30, which is approximately 22 anchoring studs per meter of frame length. Accordingly, the installation effort to drill and affix this large number of anchoring studs is relatively high. [0006] The patient bed 26 of the known PHS 30 is translated by a drive system comprising a linear motor 48 oriented between the linear rails 40, with a rotor 50 coupled to the trolley and an opposing, flat linear stator 52 co